This invention relates to an improved winch mechanism and more particularly to a winch mechanism which provides for free wheeling operation of the winch, power winding of the winch, power unwinding of the winch, and a controlled load unwinding of the winch.
Winch devices, particularly winch mechanisms driven by a small, reversible, direct current motors have in recent years been commonly used as an attachment to boat trailers and the like for movement of boats and other goods onto or off of the trailer. Typically, such winches are attached to the front end of the trailer. A cable attached to a drum of the winch may then be wound or unwound by operation by a direct current motor to thereby move a boat from the trailer or place a boat back upon a trailer.
Often it is desirable to provide for free wheeling operation of the winch unimpeded by the motor. Also, during the unloading operation from the trailer, the weight of the load may tend to cause uncontrolled or excessively fast operation of the winch. Therefore, it is desirable to be able to control the speed of operation of the unwinding of cable from the drum. Finally, it is desirable to provide an additional load in the winch mechanism so that the load being moved remains locked in position when the winching operation is complete.
Heretofore powered winches have provided some of these desired features. Typical of such prior art winch mechanisms are those shown in Ahlbin U.S. Pat. No. 3,150,861 and Ahlbin U.S. Pat. No. 3,051,447 Wood U.S. Pat. No. 3,474,922 and Alcott U.S. Pat. No. 3,773,294. However, no known winch is available which incorporates all of the features described in a single unitary winch mechanism. Thus, a need for a winch mechanism incorporating all of the described features has not heretofore been satisfied. The present invention constitutes a mechanism which provides the described objectives.